Desiccant Wheels

As a book conservator I was trained to dis-bind, wash, mend and re-sew books from different points in history.  However, a library's storage environment also plays a crucial role in the longevity of collections.  There's little to be gained from spending hours and hours treating a rare book if you have to send it back to a stacks area that is not up to par.
 
Facilities staff will always have the primary responsibility for maintaining the air handling systems, but it is important that librarians are engaged and articulate about the systems that take care of their books.  So a significant portion of my training focused on building systems, including heating, ventilating and air-conditioning (HVAC).  We had a final workshop on HVAC systems that reviewed different types of HVAC technology and concluded with a walk through of the air handlers in our classroom building. 

One of the technologies that was new at the time (1998) was using a desiccant wheel for de-humidification.  Have you noticed the little silica packets that come in boxes of shoes or electronics?  They're like that but much, much bigger.   

All of the buildings I've worked in 'til now have been older buildings with older types of HVAC systems.  My current job has been my first opportunity to see a desiccant wheel up close and I must say it was pretty exciting.  You can gete a sense of how big the wheel is from the picture above.  The yellow strap is the drive belt for the wheel, to keep it turning so that the unsaturated section of the wheel is in the airflow from the building while the saturated part is getting dried out. 

The wheels do get changed when they wear out as you can see below.  They're very, very heavy, so it is a good thing they roll.

Re-housing the Holsinger Studio Collection of Glass Plate Negatives

Guest posting by Kara M. McClurken, Head, Preservation Services

The Holsinger Studio Collection is a collection of glass plate negatives held by the Albert and Shirley Small Special Collections Library at the University of Virginia. This collection reflects a unique photographic record of life in Charlottesville and Albermarle County, Virginia, from before the turn of the century through World War I.  The collection consists of approximately 9,000 dry-plate glass negatives and 500 celluloid negatives from the commercial studio of Rufus W. Holsinger.  These images are quite popular and have been digitized and made available through our online catalog, Virgo.

Digitizing the collection presented the perfect time to re-house the originals since the digital images could be the primary means of access and the fragile originals could be placed in high density storage.  Glass plate negatives present several storage challenges since glass is fragile but heavy.  The Holsinger collection also has five sizes of glass plates: 5” x 7”, 5” x 8”, 8” x 10”, 11” x 14” and 14” x 17" which is an unusual range of sizes and there were no commercial vendors who stock housings in those sizes. We ended up working with two vendors—one to create customized boxes and spacers for the negatives, and another to create special four-flap enclosures for the largest size plate since they needed additional support.  It took a year of experimentation before we were able to finalize all the housing components that would safely store these incredibly valuable plates.

As a general rule, glass plate negatives should be stored long-side down and care should be paid as to how many negatives are in a box so that the weight of the box does not become too great. Also, care must be taken when handling the negatives, due to their fragility and weight.

four-flap for the largest sized glass-plate negative

Step one: Place negative in center of enclosure.

Step two: Fold shorter, inner flaps.

Step three: Fold longer, outer flaps.  They stay together using Velcro. 
 Make sure that any identifying information on the original housing is transferred to new housing

Step four: Carefully lift negative and place in custom storage box.  Add spacers for additional protection.

Step five: Turn box upright, place lid on box and label.  Voila!  Our negatives are now ready for storage

Note the handle with care labels.